PDGFRA and head and neck squamous cell carcinoma: In the present study, we aimed to evaluate the possible association between a panel of 19 variants in the FGF2, FGFR2, PDGFB, PDGFRA, PDGFRB, MMP2, MMP9, TIMP1, TIMP2, and TIMP3 genes and the clinical outcomes in non-surgically treated HNSCC patients who received radical RT alone or in combination with cisplatin-based CT.